Mechanism of antitumoral activity of catechols in culture

Cell lines Raji and K 562, lacking tyrosinase, and two melanotic human melanoma cell lines (IRE 1 and IRE 2), were exposed to concentrations from 5 X 10(-3) M to 10(-5) M of different phenols which are substrates of tyrosinase, i.e. l-dopa, dopamine, hydroquinone, terbutylcatechol, and of phenols which are not substrates of the tyrosinase, i.e. resorcinol, butylated hydroxyanisole and hydroquinone dimethyl ether. Cultures were carried out in the presence or in the absence of oxygen radical scavenger enzymes superoxide dismutase, catalase and peroxidase. The stability of each substance in culture medium was assayed by high performance liquid chromatography (HPLC). Results showed that: catechols which are substrates of tyrosinase decompose fully after 24 hr in medium; they are equally toxic for melanoma and non-melanoma cell lines; their toxicity increases when they are preincubated in medium for 24 hr and 48 hr before addition of cells; their toxicity is significantly reduced by addition of scavenger enzymes; on the contrary, phenols not substrates of tyrosinase are stable in medium and their toxicity is not reduced by scavenger enzymes. It is concluded that tyrosinase does not play a major role in catechol toxicity in vitro, which is probably due to some products of catechol decomposition, especially oxygen radicals, acting outside the cells.

Growth and development of biofeedback: a bibliographic analysis

A computerized search was performed, and a bibliography was prepared on the subject of biofeedback covering the years from 1964 to 1985. Growth curves were produced for various publication media. The search produced references to 2,431 journal articles, 102 books, 79 popular magazine articles, and 551 doctoral dissertations. The journal articles were sorted according to the country of publication, language, and primary topic of the journal. Citations were found from 35 countries, written in 18 languages. All the media studied showed a period of rapid growth during the early to middle 1970s, but there was a tendency for leveling off or slight decline during the early 1980s. Publication of articles in medical journals has shown the greatest growth, and more articles are published yearly in medical journals than in journals of any other discipline or all specialty journals combined. Publication in psychological journals has shown a decline since 1977. Dental, nursing, and educational journals have shown a low rate of publication of biofeedback articles, indicating little or no growth.

Value of serum diazepam and nordiazepam measurements in anxious patients

The relationship between the dose and anxiolytic effects of diazepam and the serum concentrations of diazepam and nordiazepam were examined in groups of acutely and chronically anxious patients. The results showed a significant correlation between dose and serum nordiazepam concentrations after short-term (14-day) administration, but no significant association between clinical symptoms of anxiety and serum diazepam and nordiazepam. We conclude that the main value of serum benzodiazepine measurements in anxious patients in assessing compliance, particularly in patients suspected of taking more than the recommended dose. Serum nordiazepam is a more consistent index of dosage after chronic therapy than serum diazepam because it has a longer elimination half-time.

Non-immunological hydrops fetalis. a case report

A case of hydrops fetalis which was not due to isoimmunization is presented. The condition was diagnosed antenatally by means of ultrasonography and the infant was delivered at 32 weeks' gestation. He required intensive care, but survived and is well at 18 months of age. The causation, diagnosis and management of this problem are discussed.

Treatment of prolapsed submucous fibroids

Prolapsed submucous fibroids are not uncommon, and patients present with a vaginal mass which is often necrotic and infected. This is a retrospective study of 41 such patients seen at the King Edward VIII Hospital, Durban, over a 3-year period. Twenty-eight were treated by vaginal myomectomy and 13 by abdominal hysterectomy. Postoperative morbidity was slightly higher with hysterectomy, but comparable to that for hysterectomy for unprolapsed fibroids.

Sequelae of caffeine treatment in preterm infants with apnea

Growth, neurologic, and ophthalmologic assessments were done in 21 low-birth-weight infants given caffeine for neonatal apnea and in 21 matched control infants. Caffeine significantly decreased the need for and the duration of mechanical ventilation. No difference in growth and development was noted between the control and caffeine-treated infants. A high incidence of cicatricial retrolental fibroplasia was observed in both control (10/21) and caffeine-treated infants (7/18).

Heroin addiction as a family phenomenon: a new conceptual model

The chronic relapsing nature of heroin addiction can be explained from a family systems viewpoint. The addiction cycle is part of a family pattern involving a complex homeostatic system of interlocking feedback mechanisms. These serve to maintain the addiction and consequently the overall family stability. Drug-taking usually starts at adolescence. It is related to an intense fear of separation experienced by the family in response to the addict's attempts at individuation. The family becomes stuck at a particular developmental stage. Heroin provides a solution at several levels to the dilemma of whether or not to allow him independence. Paradoxically, it permits him to simultaneously be both close and distant, "in" and "out", competent and incompetent, relative to his family of origin. This is pseudoindividuation. An understanding of these concepts, and their integration into a homeostatic model, can provide the basis for effective treatment.

The effect of various adjuvant regimens and of nematode infection on the reaginic antibody response to egg-albumin in the rat

The role of some critical components of the potentiated reagin response to egg-albumin following nematode infection in the rat are examined. The phenomenon can conveniently be described in two stages: <i>Stage 1</i>. Following injection of the antigen reagin production must be initiated before infection with the parasite. To satisfy this precondition, egg-albumin requires to be injected with an adjuvant since no detectable reagin appears if the antigen alone is injected. Adjuvants found to be successful in this system were <i>Bordetella pertussis</i>, Freund’s complete or incomplete adjuvants, <i>Corynebacterium parvum</i> in water-oil emulsion and aluminium hydroxide gel. <i>C. parvum</i> in saline suspension proved ineffective. <i>Stage 2.</i><i>Nippostrongylus brasiliensis</i> infection potentiates the circulating reagin titre up to 100 times. Attempts to potentiate by substituting <i>B. pertussis</i> for a parasite infection in stage 2 were unsuccessful.

Inhibition of allergic reactions due to competition for mast cell sensitization sites by two reagins

The ability of unrelated or incidental reagin to interfere competitively with mast cell sensitization by specific reagin has been examined using an experimental system whereby rats are induced to produce high levels of reaginic (IgE) antibody to two antigens. It is shown that passive sensitization by a reaginic antibody is inhibited (a) by simultaneous injection with a second reagin directed against another antigen, the degree of inhibition being related directly to the dose of the second serum or (b) if the test animal is actively producing unrelated reagin.

The skin test sensitivity of rats actively producing high levels of two reagins as opposed to only one is also discussed. The results are presented with particular reference to the interpretation of PCA and other skin tests and to the possible importance of interference effects in multiple allergies.

Potentiated reagin response to egg albumin in Nippostrongylus brasiliensis infected rats. II. Time course of the reagin response

The potentiated reagin response induced by infection with the nematode Nippostrongylus brasiliensis after sensitization with egg albumin and Bordetella pertussis vaccine was investigated to reveal the time course of the potentiated reagin response and the maximum reagin titre attained. The potentiated reagin response was found to be transitory but during this period high reagin titres to egg albumin were recorded.

Rat sensitized to egg albumin and treated with N. brasiliensis crude worm extract instead of an infection did not show a potentiated response.